‘I began to explore my voice because there was a slight change so I had to adjust the technique,’ he told presenter Suzy Klein, ‘I went on a journey – for a singer to change even a little bit is a big deal.’

‘I’ve always had respect for my voice. If I had two days between performances, I wouldn’t sing. But now, my repertoire is changing with new operas. In the past with Rossini and Donizetti I never needed to push but now I’m singing La favourite [recently at the Théâtre des Champs-Elysées in Paris] and Roméo et Juliette [upcoming in Lima], it’s very important not to overdo it because it’s a very delicate instrument.’

‘I’ve always sung without really thinking what I was doing – it was easy. That time I had to adjust made me look at other singers and how they sing. I read books on Caruso. Also, when you have kids, you become a different person - now, I like rehearsing; I never liked rehearsing! I try to be with my kids when I’m preparing for a role and I’m not happy when they’re not here!’

Though he is much in-demand at opera houses around the world, Juan Diego has found it easy to slip back into the role of Tonio, and Laurent Pelly’s much-loved production: Sometimes the director asks me “How was it Juan Diego? Was it to the right or the left?” and I say “To the right”. It’s like a muscle memory – arrive and you know where to go.’

Off-stage Juan Diego organizes a foundation in his native Peru, which runs classical workshops with over 2,000 disadvantaged children: ‘We have 15 centres where children perform in orchestras and choruses as well as learn how to make instruments. You give these children opportunities and values, something that makes them happier and they aren’t poor anymore – they look at life in a different way.’